Infinitely variable change-speed gear



June 2% 119% A. WULLSCHLEGER INFINITELY VARIABLE CHANGE-SPEED GEAR Filed Sept. 2, 1947 Patented June 20, 1950 OFFICE INFINITELY VARIABLE CHANGE-SPEED v GEAR August Wullschleger, Olten, Switzerland Application September 2, 1947, Serial No. 771,617

' In Switzerland June 15, 1945 Section 1, Public Law 690, August 8, 1946 k Patent expires June 15, 1965 The invention relates to an infinitely variable, electrically driven change-speed mechanism, which may be used as a unit or as part of a machine tool. "The novelty lies in the feature that notonly the armature but also the field or so called stator of the electric motor is rotatably supported 'and that at least two change-speed devices are provided which are in operative connection with each other, oneof thedevices being variable. The field and armature have different speeds and the resultant movement of rotation is transmitted by means of a planetary gearing unit to the machine doing work.

The new "mechanism allows the availablev "speeds to be infinitely varied within verywide limits, the means therefor being very simple and easy to operate. 1

One embodiment of the subject matter of the invention is illustrated in draWingL-in which'z' Fig. l is a longitudinal section, and

Fig. 2 an end View of the mechanism. 7

In the interior of the conical belt pulley I is the electric motor 2, 2a, the armature 2a of which is'fi'xedly attached to the armature shaft 1. In .the case of a motor type with squirrel-cage rotor, the current is introduced for instance through .brush-holders 3 and slip rings 4 to the motor part 2, or from the brush-holder 6 through slip rings 5 and the shaft 1 tothe motor part 2a.

The conical belt pulley I is, with the built in motor part 2, supported by the bearing shields .and bearings 8, 8a so that it can rotate freely on Ithe shaft 1. Motor part 21;, belt pulley 9 and toothed pinion or sun gear III are connected firmly to shaft 1. The orbit gear Ila is supported in the bearing 12 by means of the bushing Ho and serves at the same time as the bearing for the shaft 1. In addition, the shaft is supported in the bearing [3. The planet gear 24 is rotatably supported on pin 25 and engages on the one hand with the sun gear l and on the other hand with the orbit gear Ha. The pin 25 is fixed in the boss 26 and is therefore rigidly connected to the motor part 2.

The bearings l2 and [3 are fixed on the frame It. In order to keep the belts I! and I8 tight, the bearings l and I6 are arranged movably on the frame It. Within these bearings l5 and It the axle I9 is located, on which the conical pulley 2B is supported by the bearings 22 and 23. The belt pulley 2| is rigidly connected to the belt pulley 20.

The pulleys l and 20 along with the laterally the accompanying 5 Claims. (Cl. 74-689) 2 displaceable belt I! on them, form a cone ear. The belt pulley 9, along with the pulley 2 I, forms a belt gear with fixed speed-ratio, for instance with V-belts l8. Consequently, through the transmission members I, 9, l8, 2|, 20, lland l the motor part 2a is brought into a speed ratio with the motor part 2, which can be varied within a certain range by laterally displacing the belt 11. One condition for the speed variator with field and armature (2 and 2a) rotating in the same direction, i. e. with open belts l1 and I8, is that the variable speed-ratio between the'field 2 and armature 2a cannot be- 1:1, but may have any other desired value. With the parts 2 and 2a rotating in opposite directions to each other, i. e. with one of the belts l1 and I8 open and the other belt crossed, this limiting condition does not exist. Y

' In the arrangement shown in the drawing, assuming the motor to be a 4-pole 3-phase motor having a normal speed of approximately 1500 R. P. M., the operation of the device is as follows: As the armature 2a. rotates it drives the cone pulley 20 by means of the pulleys 9 and 21 and the belt l8. The pulley 20, in turn, by means of the belt 'l'l drivesthe cone pulley Iand therewith the field element 2. The motor elements 2 and Zathus drive the planetary gear unit in the usual manner; Assuming the belts ll'and Hi to be open, both motor'elements 2 and 211 will rotate in a clockwise direction, as shown in Fig. 2. Since the difference in the speed of rotation of the motor elements 2 and 2a will always be about 1500B. P. M., the speed ratio between the armaa speed of 750 R. P. M. the resultant speed between the two elements is 1500 R. P. M.

An equation can now be established wherein the rotation of the armature 2a is designated as I and the field 2 has a rotation as designated by II or 110,, the orbit gear Ila will have a resultant rotational speed as indicated by III. If both belts H and I8 are open the equation is I-II- III, and I-II=1500 R. P. M. If one of the belts I! or I8 is crossed the equation becomes I+II III, and I+II=1500 R. P. M.

By a proper choice of the speed ratios of the belt and planet gears, this rotation III may remain always in the same direction between the upper and lower speed ratios, or it may assume an diiferent directions between these limits.

This variable rotation III of the orbit ear Ha may be transmitted to a working machine in a suitable manner either by means of belt, toothed on chain gear or by direct coupling to the machine. By-a suitable utilisation .of the-attributes of theelectric motor (for instance, phase angle, pole changing control, etc. in 3-phase motors), it is possible to alter the direction of the rotation movement III and to move the speed range with the existing change-speed ratios.

What I wish to secure by U. S. patent is:

1. In a variabl change speed gear thecombination of an electric motor having relatively movable field and armature-=elements, said=iield element being constructed as a cone -pulley, -a second cone pulley, a transmission structure the tween said armature element andrsaid :second cone pulley, said transmission structure having a fixed ratio, a belt trained over said cone "pulleys and axially shiftable thereon and adapted to impart infinitely variable speed to :said first smotor 1 element, a-driven-part', :and a transmission-assembly interposed between said field element sand said driven *part.

2. In a variable change speed gear, zthe combination of an electric motor having :relatively movable field and armature elements, :said field element being constructed as a cone :pu'lley, :a second cone pul-ley arthird pulleysofmniform diameter fixed to said armature element, .:a :fourth pulley of uniform #diameter fixed to said v second cone pulley, a transmission beltztrainedsoversaid third and fourth pulleys, ianother loelttrained oversaid first andsecondzconezpulleyssand axially 'shiftable thereon, a zdrivenapart, and a :transmission assembly interposed betweenssaid-znotor elements and-said driven part.

3. In a variabl change speed gear, the combination of :an electric motor :having relatively movable field and armature elements, :said field element beingoconstructedrasa- .conezpulley, 1a=:s.ec ondzconezpulley,aztransmission'rstructurekbetween said armature element and :said .aseoond cone pulley, :said transmission structure having a: fixed ratio, a belt "trained. over. :said-aeone pulleys and axially shiftable'thereomto irnpartjnfinitely variable. speed :to said :field elementgaJdriven part, and a transmission assembly ina'thezform "of :a planetary gearing 'un'itu interposed between; said motor elementsgand .saidadriyennpart; a-.planetary .gear of this transmissionvassembly beingmounted on saidiield relementmoneepulley torevolveabout the-axis ofthe motor elements.

:4. -In' a rvariablecchange :Speed' gear, the -:com- &bination of an electric :motor having relatively -movable field and armature -elements, .a zframe structure, rbearingsifixedly;mounted'imsaid.-frame transmission assembly in the form of a planetary gearing unit interposed between said motor elements and said driven part and deriving impetus fi'om-ibotlisaidrmotor elements to impart variable speed to said driven part.

.5..In .a variable change speed gear, the combination -of an electric motor having relatively rotatable field and armature elements, a frame structure, an armature shaft on which said armature element is fixed, bearings fixedly mounted in .:said:i-ramezstructure;for rotatablysupportingzsaid armature-shaft, asaidifield element :being menstructedsas :a =:.cone rpulley 1 and bein :rotatably mounted on said armature shaft, a SGCDDd-ZGOHE ;pulley,--:b.earings ginssaid fframe structureimovably mounted :jor supporting :asaidsecond -cone- :pulle y, 1a third:;pulley:.of .uniform diameterv fixed .to=said armature shatt, a :fourth r-pull'ey of uniform. ditameter ffiXed to said :second cone rpulley, a .belt "trained over said-third and fourthpulleystodrive said :second 100116 apulley at a .speed -.-of rpredetermined .ratio :to the -=speed.--,of .--said :arm'ature Tele- -ment, a second belt ;trained-.over :said.clirst.aand

second cone pulleys andsaxially-shiitablethereon to impart infinitelyvariabl :speed to-said-field 1 elementardriven part,-and {a transmissioniassembly in'the form of'amlanetary gearing-.unitiinterposed between said motor elements iandsaid drivempart, =theesunigear of saidsplaneta yr earlug-unitbeing secured tosaidz-arm-atureshatt, :the

planet gear of said unit beingrotatabl-yattached to said field. elementtat z-a distancefrom :the'axis of rotationiof .said fieldaelement, ,saidrdriven part comprising stherintemally toothed orbit gear of said runit.

.AUGUSFI WULLSCI-ILEGER.

REFERENCES ,CITED The "following greferences are ,Of record in sthe file ofthis patent:

UNITED STATES 'PAIENTS Number .Name fDate 344,148 Riddell ...Eeb. 1 7, .1907 1,330,398 .Seidel..- Feb. l.0, 1920 1,746,029 .Chorlton Feb. ;4, .1930 2,164,818 Heyer etial (July 4,, .1939 

